GCOS Implementation Plan - WMO

Implementation Plan for the Global Observing System for Climate in Support of the UNFCCC
(2010 Update)
Efforts should be made to (a) reduce uncertainties in estimates of mass balance and (b) derive better
measurements of ice-sheet topography and velocity through improved observation of ice sheets and
outlet glaciers. This includes utilizing existing satellite interferometric synthetic aperture radar (InSAR)
data to measure ice velocity, using observations of the time-varying gravity field from satellites to
estimate changes in ice sheet mass, and monitoring changes in ice sheet topography using tools,
such as satellite radar (e.g., Envisat and Cryosat-2), lasers (e.g., ICESat-1/2), and wide-swath
altimeters (see Action T20).
Monitoring the polar regions with numerous satellites at various wavelengths is essential to detect
change (i.e., melt area) and to understand processes responsible for the accelerated loss of ice sheet
ice and the disintegration of ice shelves in order to estimate future sea level rise. Further, aircraft
observations of surface elevation, ice thickness, and basal characteristics should be utilised to ensure
that such information is acquired at high spatial resolution along specific routes, such as glacier flow
lines, and along transects close to the grounding lines. In situ measurements (e.g., of firn temperature
profile and surface climate) are equally important in assessing surface mass balance and
understanding recent increases in mass loss.
Action T18
Action: Ensure continuity of in situ ice sheet measurements and fill critical measurement gaps.
Who: Parties, working with WCRP CliC, IACS, and the Scientific Committee on Antarctic Research
(SCAR).
Time-Frame: Ongoing.
Performance Indicator: Integrated assessment of ice sheet change supported by verifying
observations.
Annual Cost Implications: 10-30M US$ (Mainly by Annex-I Parties).
Action T19
Action: Research into ice sheet model improvement to assess future sea level rise.
Who: WCRP CliC sea level cross-cut, IACS, and SCAR.
Time-Frame: International initiative to asses sea level rise within 5+ years
Performance Indicator: Reduction of sea level rise uncertainty in future climate prediction from
ice sheet contributions to within 20% of thermal expansion of the ocean.
Annual Cost Implications: 1-10M US$ (Mainly by Annex-I Parties).
Action T20 [IP-04 T14]
Action: Ensure continuity of laser, altimetry, and gravity satellite missions adequate to monitor ice
masses over decadal timeframes.
Who: Space agencies, in cooperation with WCRP CliC and TOPC.
Time-Frame: New sensors to be launched: 10-30 years.
Performance Indicator: Appropriate follow-on missions agreed.
Annual Cost Implications: 30-100M US$ (Mainly by Annex-I Parties).
ECV – Permafrost
Frozen ground (as measured by permafrost temperatures and depth of seasonal freezing/thawing)
reacts sensitively to climate and environmental change in high latitude and mountain regions.
Corresponding changes result in the thermal mode of permafrost and subsurface conditions and have
important impacts on terrain stability, coastal erosion, surface and subsurface water, the carbon cycle,
and vegetation development. Combined monitoring of meteorological and hydrological variables, soil
and vegetation parameters, carbon dioxide and methane fluxes, and the thermal mode of the active
layer and permafrost on upgraded “reference sites” is the recommended observing approach.
Standardised in situ measurements are essential, both to calibrate and to verify regional and global
climate models.
The Global Terrestrial Network for Permafrost (GTN-P), coordinated by the International Permafrost
Association (IPA), forms a GCOS/GTOS baseline network for these variables. The Geological Survey
of Canada (Ottawa) maintains borehole metadata files and coordinates thermal data management
and dissemination. Every five years, the NSIDC prepares and distributes a Circumpolar Active Layer
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